Say goodbye to all your “low battery” woes, as this innovation from US researchers is on the brink of changing our smartphones, and in fact any battery dependent technology, forever.
Scientists believe they have created a battery-free cell phone that uses power from ambient radio signals to work and doesn’t require any conventional battery to make calls or perform any other basic cellphone functions.
“We’ve built what we believe is the first functioning cellphone that consumes almost zero power,” says one of the researchers, Shyam Gollakota from the University of Washington.
“To achieve the really, really low power consumption that you need to run a phone by harvesting energy from the environment, we had to fundamentally rethink how these devices are designed.”
The researchers managed to pull this off by changing the mechanism of conventional cellular transmission. Usually, the conventional cellular transmission uses on the spot conversion of analog signals picked by the mic to digital ones that are then sent across the network. But this conversion and propagation require a whole lot of energy to perform, approximately 800 milliwatts which is thousands of times more than the 3.5 microwatts the latest batteryless cellphone needs to operate.
So rather than wasting the energy in conversion, the device keeps the data in analog and instead registers tiny vibrations from the mic during a call using a technique called backscatter which transmits the signals to a nearby base station several meters away.
So for now, you’ll need to be in close vicinity to a base station for the technique to work since the technology doesn’t use regular cellular towers, but this could change in the future if the viability of the system is proved.
“You could imagine in the future that all cell towers or Wi-Fi routers could come with our base station technology embedded in it,” says one of the team, Vamsi Talla.
“And if every house has a Wi-Fi router in it, you could get battery-free cellphone coverage everywhere.”
One of the researcher claims that this idea came to him after reading an incident during the Cold War, where the Soviets placed a similar kind of battery-less listening device on the Great Seal of United States, before presenting the audio to the American Ambassador in Moscow as a gift.
“My dad was a spy in the Cold War, so I heard stories about the Great Seal bug when I was a kid,” one of the researchers, Joshua Smith, told Mark Harris at Wired.
“I wondered if analogue backscatter could be software-controlled and turned from a curiosity for spooks into a technology that everyone could use.”
While it might take the technology years to get mainstream, it’s still a very promising prospect for future research.
“If you had to pick one device to make battery-free, what would you pick?” says Smith.
“A cell phone is one of the most useful objects there is. Now imagine if your battery ran out and you could still send texts and make calls.”